The Dreadnoughtocetus has a mouth similar to a cross between that of the Baleen and Sperm Whales of Earth, and other carnivores. It's clade is unique like that, possessing large mouths that can tackle a wide variety of food sources. The top jaw has a long row of baleen, a filamentous set of teeth used to sieve plankton out of the water, before its tongue passes the hundreds of thousands of caught organisms into its throat. The lower jaw possesses several conical or banana shaped teeth, which can stab through a nutritious snack, like, for example, a Krakerb. The toothed jaw is not used often in the main feeding process, as the baleen tends to get in the way, which may cause pain and damage to it if an individual bites down hard enough. The Dreadnoughtocetus is an indiscriminatory omnivore: a filter feeder which can also engage in raptorial feeding. Plankton, usually microscopic organisms which cannot swim against the current, are the staple diet for this leviathan, making up over 85% of it.  The Dreadnoughtocetus is also known to eat larger organisms, which means that it often comes into contact with a massive Malacopod known as the Deep Sea Kraken, which is the second largest complex animal on Kerbin. These two titans have been at an evolutionary war, ever since the Dreadnoughtocetus first evolved. Both animals are known to occasionally eat each other's young. Battles between the two are relatively uncommon, and they often take place in the depths below. Witnessing a battle between a Dreadnoughtocetus and a Deep Sea Kraken, especially if said battle takes place close to the surface, can be an experience of a lifetime.

Due to its size and occasional ferocity, the Dreadnoughtocetus has few, if any, natural predators. The Black Shark, other Tiburonians and other creatures do tend to feed on weaker individuals, as well as the carcasses. Recently, the Dreadnoughtocetus has also been hunted by Kerbals, for its meat and blubber, which was used to make candles and similar materials. Such hunting has been mostly banned in most Kerbal jurisdictions, but some illegal hunting does take place.

The Dreadnoughtocetus displays minor sexual dimorphism. Males are longer, with elongated heads, whilst females are fatter and less manoeuverable. Dreadnoughtocetuses, or Dreadnoughtoceti, often make yearly trips between their feeding grounds around Kerbin's oceans and breeding grounds closer to the equator. These migration patterns loosely follow those of Earth whales. Females often live in small groups, often consisting of a matriarch and her offspring. Males often live alone, but some occasionally form bachelor groups. When at the breeding grounds, males often seek out females, approaching one and whiffing her scent to see if she's receptive. If she is, the two will pair up and defend each other from other suitors, for a few days of courting. After this period, the male will use his prehensile, tree like intromittent organ to inseminate the female, after which they separate. The female can be pregnant for around 1.25 Kerbinian years, giving birth to a single calf, which will suckle off of her very fatty milk. After the birth of the calf, the female is unable to breed for another 1 to 2 years.